The present invention is generally related to electrical arc detection, more particularly to optical signal detection during arcing fault in electrical distribution systems.
Arc flash is the result of a rapid energy release due to an arcing fault between phase conductors, phase and neutral conductors, or phase and ground conductors. An arc flash can produce high heat, intense light, pressure waves, and sound/shock waves similar to that of an explosion. However, the arcing fault current is usually lower than a short circuit or bolted fault current, and hence delayed or no tripping of circuit breakers is expected unless the breakers are selected that are designed to handle an arcing fault condition.
Detection of arc flash, indicative of an arcing event, can be useful in mitigating the undesirable arcing conditions in electrical system or equipment, such as electrical distribution equipment or systems. One known technique for detecting arcing events involves the use of optical detectors to detect visible light and thereby to sense the arc flash associated with an arcing event. However, this technique may give raise to erroneous detection as the sensors may detect undesirable light from other sources such as lamps and even daylight. Another technique is to use current monitors to evaluate current perturbations in a conductor indicative of an arcing event. However, this technique may require onerous processing demands resulting in an undesirably long reaction time for identifying an arcing event. Another technique is to use pressure sensors to monitor the increase in pressure indicative of an arcing event. However, this technique may require significant time before pressure increases to actionable levels, resulting in long reaction time in mitigating an arcing event.
Therefore, there is a need for arc flash detection technique that provides reliable and early detection and effective mitigation to avoid damage to electrical equipments and to protect the personnel.